The presented project, called VirtualDive, implements an educational, virtual-reality-based environment dedicated for children. The user "immersion" into the virtual underwater world permits him to interact with different fish species as well as to perturb the simulated environment conditions, such as temperature and pollution. Educational actions, as cleaning the environment or plant, are expected to emerge due to the participative immersive simulation. The virtual environment architecture is reactive-agent-based, while the user-environment and user-agent interactions are stimuli based. We have used VR-techniques in project implementation, VRML and C++ languages for modeling and AR?eVi API for rendering.